x402-gated Stripe invoice endpoint on Base, pay-per-call with USDC.
What it does
This endpoint at lowpaymentfee.com provides "Premium API Access" behind an x402 payment challenge. The specific resource path (`/api/v1/stripe/invoices/135`) suggests it returns or processes a Stripe invoice record. Payment is settled on the Base network using USDC (contract 0x8335…2913) with a maximum cost of $0.02 per request (20,000 base units at 6 decimals). The endpoint accepts HTTP POST and returns application/json.
lowpaymentfee.com is a broader platform offering multiple x402-gated API categories including data & analytics, AI/ML inference (sentiment analysis, summarization, classification, embeddings), finance & Web3 data (price feeds, exchange rates, token quotes, gas estimates), and infrastructure utilities (geocoding, validation, conversion, generation). All endpoints are advertised at $0.02 per request with no API keys, no rate limits, and no minimum commitments. Payments settle on the Base L2 network.
Documentation is extremely sparse — the /docs, /pricing, /api, and /README pages all render only a "Connect wallet" prompt with no further technical detail. There is no OpenAPI spec, no request/response schema documentation, and no usage examples available. The specific behavior of the `/stripe/invoices/135` endpoint (whether it retrieves an existing invoice, creates one, or performs some other operation) is not documented and must be inferred from the path alone.
Capabilities
Use cases
- —Retrieving or processing Stripe invoice data via a single pay-per-call request
- —Integrating x402 payment-gated invoice access into agent workflows
- —Accessing financial data endpoints without API key registration
Fit
Best for
- —Agents that can settle x402 payments in USDC on Base
- —Developers wanting keyless, pay-per-use API access
- —Quick one-off invoice data retrieval without subscription commitments
Not for
- —Users needing detailed API documentation or OpenAPI specs before integration
- —High-volume batch invoice processing where per-call pricing adds up
- —Anyone without a Base-compatible USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/stripe/invoices/135 \
-H "X-PAYMENT: <x402-payment-token>" \
-H "Content-Type: application/json"Endpoint
Quality
The endpoint is live (402 challenge confirmed) and pricing is clear ($0.02 USDC on Base), but there is no documentation, no request/response schema, no examples, and the specific purpose of this invoice endpoint is unclear. The docs pages are empty beyond a wallet-connect prompt.
Warnings
- —No OpenAPI spec or request/response schema available
- —All documentation pages (/docs, /pricing, /api, /README) render only 'Connect wallet' with no technical content
- —The specific behavior of /api/v1/stripe/invoices/135 is undocumented — unclear whether it retrieves, creates, or modifies an invoice
- —No example requests or responses available to verify endpoint functionality
Citations
- —Endpoint returns 402 with x402 challenge requiring USDC payment on Base networkhttps://lowpaymentfee.com/api/v1/stripe/invoices/135
- —maxAmountRequired is 20000 base units of USDC (6 decimals = $0.02)https://lowpaymentfee.com/api/v1/stripe/invoices/135
- —All endpoints priced at $0.02 per request with no API keys, no rate limitshttps://lowpaymentfee.com
- —Platform offers APIs across data/analytics, AI/ML, finance/Web3, and infrastructure categorieshttps://lowpaymentfee.com